found that at refrigeration temperatures the colour underwent severe
changes during vacuum storage. In these tests, the values of a* and L*
in the HHP-treated samples showed a significant reduction after two
days of storage, while a* values remained constant during the rest of
the period. Jung, Ghoul, and de Lamballerie-Anton (2003), performed
HHP experiments using vacuum packed meat in polyethylene film; as
this plastic film material has a high oxygen gaseous permeability a
significant decrease in a* values between the 1st and 7th days of storage
was reported (a* b 9) after a treatment at 520 MPa. The authors
assumed that the variation of a* values could be correlated to the accumulation
of metmyoglobin in the samples. These results contrast with
the obtained in the present work because in our case a barrier film
(Cryovac BB4L) was used avoiding the formation of metmyoglobin
and leading to a* values that remained N9 during storage.